/**
 * @file
 * Dynamic pool memory manager
 *
 * lwIP has dedicated pools for many structures (netconn, protocol control blocks,
 * packet buffers, ...). All these pools are managed here.
 *
 * @defgroup mempool Memory pools
 * @ingroup infrastructure
 * Custom memory pools

 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

#include "lwip/opt.h"

#include "lwip/memp.h"
#include "lwip/sys.h"
#include "lwip/stats.h"

#include <string.h>

/* Make sure we include everything we need for size calculation required by memp_std.h */
#include "lwip/pbuf.h"
#include "lwip/raw.h"
#include "lwip/udp.h"
#include "lwip/tcp.h"
#include "lwip/priv/tcp_priv.h"
#include "lwip/ip4_frag.h"
#include "lwip/netbuf.h"
#include "lwip/api.h"
#include "lwip/priv/tcpip_priv.h"
#include "lwip/priv/api_msg.h"
#include "lwip/sockets.h"
#include "lwip/netifapi.h"
#include "lwip/etharp.h"
#include "lwip/igmp.h"
#include "lwip/timeouts.h"
/* needed by default MEMP_NUM_SYS_TIMEOUT */
#include "netif/ppp/ppp_opts.h"
#include "lwip/netdb.h"
#include "lwip/dns.h"
#include "lwip/priv/nd6_priv.h"
#include "lwip/ip6_frag.h"
#include "lwip/mld6.h"

#define LWIP_MEMPOOL(name,num,size,desc) LWIP_MEMPOOL_DECLARE(name,num,size,desc)
#include "lwip/priv/memp_std.h"

const struct memp_desc *const memp_pools[MEMP_MAX] =
{
#define LWIP_MEMPOOL(name,num,size,desc) &memp_ ## name,
#include "lwip/priv/memp_std.h"
};

#ifdef LWIP_HOOK_FILENAME
#include LWIP_HOOK_FILENAME
#endif

#if MEMP_MEM_MALLOC && MEMP_OVERFLOW_CHECK >= 2
#undef MEMP_OVERFLOW_CHECK
/* MEMP_OVERFLOW_CHECK >= 2 does not work with MEMP_MEM_MALLOC, use 1 instead */
#define MEMP_OVERFLOW_CHECK 1
#endif

#if MEMP_SANITY_CHECK && !MEMP_MEM_MALLOC
/**
 * Check that memp-lists don't form a circle, using "Floyd's cycle-finding algorithm".
 */
static int
memp_sanity(const struct memp_desc *desc)
{
    struct memp *t, *h;

    t = *desc->tab;
    if (t != NULL)
    {
        for (h = t->next; (t != NULL) && (h != NULL); t = t->next,
                h = ((h->next != NULL) ? h->next->next : NULL))
        {
            if (t == h)
            {
                return 0;
            }
        }
    }

    return 1;
}
#endif /* MEMP_SANITY_CHECK && !MEMP_MEM_MALLOC */

#if MEMP_OVERFLOW_CHECK
/**
 * Check if a memp element was victim of an overflow
 * (e.g. the restricted area after it has been altered)
 *
 * @param p the memp element to check
 * @param desc the pool p comes from
 */
static void
memp_overflow_check_element_overflow(struct memp *p, const struct memp_desc *desc)
{
#if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
    u16_t k;
    u8_t *m;
    m = (u8_t *)p + MEMP_SIZE + desc->size;
    for (k = 0; k < MEMP_SANITY_REGION_AFTER_ALIGNED; k++)
    {
        if (m[k] != 0xcd)
        {
            char errstr[128] = "detected memp overflow in pool ";
            strcat(errstr, desc->desc);
            LWIP_ASSERT(errstr, 0);
        }
    }
#else /* MEMP_SANITY_REGION_AFTER_ALIGNED > 0 */
    LWIP_UNUSED_ARG(p);
    LWIP_UNUSED_ARG(desc);
#endif /* MEMP_SANITY_REGION_AFTER_ALIGNED > 0 */
}

/**
 * Check if a memp element was victim of an underflow
 * (e.g. the restricted area before it has been altered)
 *
 * @param p the memp element to check
 * @param desc the pool p comes from
 */
static void
memp_overflow_check_element_underflow(struct memp *p, const struct memp_desc *desc)
{
#if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
    u16_t k;
    u8_t *m;
    m = (u8_t *)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
    for (k = 0; k < MEMP_SANITY_REGION_BEFORE_ALIGNED; k++)
    {
        if (m[k] != 0xcd)
        {
            char errstr[128] = "detected memp underflow in pool ";
            strcat(errstr, desc->desc);
            LWIP_ASSERT(errstr, 0);
        }
    }
#else /* MEMP_SANITY_REGION_BEFORE_ALIGNED > 0 */
    LWIP_UNUSED_ARG(p);
    LWIP_UNUSED_ARG(desc);
#endif /* MEMP_SANITY_REGION_BEFORE_ALIGNED > 0 */
}

/**
 * Initialize the restricted area of on memp element.
 */
static void
memp_overflow_init_element(struct memp *p, const struct memp_desc *desc)
{
#if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0 || MEMP_SANITY_REGION_AFTER_ALIGNED > 0
    u8_t *m;
#if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
    m = (u8_t *)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
    memset(m, 0xcd, MEMP_SANITY_REGION_BEFORE_ALIGNED);
#endif
#if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
    m = (u8_t *)p + MEMP_SIZE + desc->size;
    memset(m, 0xcd, MEMP_SANITY_REGION_AFTER_ALIGNED);
#endif
#else /* MEMP_SANITY_REGION_BEFORE_ALIGNED > 0 || MEMP_SANITY_REGION_AFTER_ALIGNED > 0 */
    LWIP_UNUSED_ARG(p);
    LWIP_UNUSED_ARG(desc);
#endif /* MEMP_SANITY_REGION_BEFORE_ALIGNED > 0 || MEMP_SANITY_REGION_AFTER_ALIGNED > 0 */
}

#if MEMP_OVERFLOW_CHECK >= 2
/**
 * Do an overflow check for all elements in every pool.
 *
 * @see memp_overflow_check_element for a description of the check
 */
static void
memp_overflow_check_all(void)
{
    u16_t i, j;
    struct memp *p;
    SYS_ARCH_DECL_PROTECT(old_level);
    SYS_ARCH_PROTECT(old_level);

    for (i = 0; i < MEMP_MAX; ++i)
    {
        p = (struct memp *)LWIP_MEM_ALIGN(memp_pools[i]->base);
        for (j = 0; j < memp_pools[i]->num; ++j)
        {
            memp_overflow_check_element_overflow(p, memp_pools[i]);
            memp_overflow_check_element_underflow(p, memp_pools[i]);
            p = LWIP_ALIGNMENT_CAST(struct memp *, ((u8_t *)p + MEMP_SIZE + memp_pools[i]->size + MEMP_SANITY_REGION_AFTER_ALIGNED));
        }
    }
    SYS_ARCH_UNPROTECT(old_level);
}
#endif /* MEMP_OVERFLOW_CHECK >= 2 */
#endif /* MEMP_OVERFLOW_CHECK */

/**
 * Initialize custom memory pool.
 * Related functions: memp_malloc_pool, memp_free_pool
 *
 * @param desc pool to initialize
 */
void
memp_init_pool(const struct memp_desc *desc)
{
#if MEMP_MEM_MALLOC
    LWIP_UNUSED_ARG(desc);
#else
    int i;
    struct memp *memp;

    *desc->tab = NULL;
    memp = (struct memp *)LWIP_MEM_ALIGN(desc->base);
    /* create a linked list of memp elements */
    for (i = 0; i < desc->num; ++i)
    {
        memp->next = *desc->tab;
        *desc->tab = memp;
#if MEMP_OVERFLOW_CHECK
        memp_overflow_init_element(memp, desc);
#endif /* MEMP_OVERFLOW_CHECK */
        /* cast through void* to get rid of alignment warnings */
        memp = (struct memp *)(void *)((u8_t *)memp + MEMP_SIZE + desc->size
#if MEMP_OVERFLOW_CHECK
                                       + MEMP_SANITY_REGION_AFTER_ALIGNED
#endif
                                      );
    }
#if MEMP_STATS
    desc->stats->avail = desc->num;
#endif /* MEMP_STATS */
#endif /* !MEMP_MEM_MALLOC */

#if MEMP_STATS && (defined(LWIP_DEBUG) || LWIP_STATS_DISPLAY)
    desc->stats->name  = desc->desc;
#endif /* MEMP_STATS && (defined(LWIP_DEBUG) || LWIP_STATS_DISPLAY) */
}

/**
 * Initializes lwIP built-in pools.
 * Related functions: memp_malloc, memp_free
 *
 * Carves out memp_memory into linked lists for each pool-type.
 */
void
memp_init(void)
{
    u16_t i;

    /* for every pool: */
    for (i = 0; i < LWIP_ARRAYSIZE(memp_pools); i++)
    {
        memp_init_pool(memp_pools[i]);

#if LWIP_STATS && MEMP_STATS
        lwip_stats.memp[i] = memp_pools[i]->stats;
#endif
    }

#if MEMP_OVERFLOW_CHECK >= 2
    /* check everything a first time to see if it worked */
    memp_overflow_check_all();
#endif /* MEMP_OVERFLOW_CHECK >= 2 */
}

static void *
#if !MEMP_OVERFLOW_CHECK
do_memp_malloc_pool(const struct memp_desc *desc)
#else
do_memp_malloc_pool_fn(const struct memp_desc *desc, const char *file, const int line)
#endif
{
    struct memp *memp;
    SYS_ARCH_DECL_PROTECT(old_level);

#if MEMP_MEM_MALLOC
    memp = (struct memp *)mem_malloc(MEMP_SIZE + MEMP_ALIGN_SIZE(desc->size));
    SYS_ARCH_PROTECT(old_level);
#else /* MEMP_MEM_MALLOC */
    SYS_ARCH_PROTECT(old_level);

    memp = *desc->tab;
#endif /* MEMP_MEM_MALLOC */

    if (memp != NULL)
    {
#if !MEMP_MEM_MALLOC
#if MEMP_OVERFLOW_CHECK == 1
        memp_overflow_check_element_overflow(memp, desc);
        memp_overflow_check_element_underflow(memp, desc);
#endif /* MEMP_OVERFLOW_CHECK */

        *desc->tab = memp->next;
#if MEMP_OVERFLOW_CHECK
        memp->next = NULL;
#endif /* MEMP_OVERFLOW_CHECK */
#endif /* !MEMP_MEM_MALLOC */
#if MEMP_OVERFLOW_CHECK
        memp->file = file;
        memp->line = line;
#if MEMP_MEM_MALLOC
        memp_overflow_init_element(memp, desc);
#endif /* MEMP_MEM_MALLOC */
#endif /* MEMP_OVERFLOW_CHECK */
        LWIP_ASSERT("memp_malloc: memp properly aligned",
                    ((mem_ptr_t)memp % MEM_ALIGNMENT) == 0);
#if MEMP_STATS
        desc->stats->used++;
        if (desc->stats->used > desc->stats->max)
        {
            desc->stats->max = desc->stats->used;
        }
#endif
        SYS_ARCH_UNPROTECT(old_level);
        /* cast through u8_t* to get rid of alignment warnings */
        return ((u8_t *)memp + MEMP_SIZE);
    }
    else
    {
        LWIP_DEBUGF(MEMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("memp_malloc: out of memory in pool %s\n", desc->desc));
#if MEMP_STATS
        desc->stats->err++;
#endif
    }

    SYS_ARCH_UNPROTECT(old_level);
    return NULL;
}

/**
 * Get an element from a custom pool.
 *
 * @param desc the pool to get an element from
 *
 * @return a pointer to the allocated memory or a NULL pointer on error
 */
void *
#if !MEMP_OVERFLOW_CHECK
memp_malloc_pool(const struct memp_desc *desc)
#else
memp_malloc_pool_fn(const struct memp_desc *desc, const char *file, const int line)
#endif
{
    LWIP_ASSERT("invalid pool desc", desc != NULL);
    if (desc == NULL)
    {
        return NULL;
    }

#if !MEMP_OVERFLOW_CHECK
    return do_memp_malloc_pool(desc);
#else
    return do_memp_malloc_pool_fn(desc, file, line);
#endif
}

/**
 * Get an element from a specific pool.
 *
 * @param type the pool to get an element from
 *
 * @return a pointer to the allocated memory or a NULL pointer on error
 */
void *
#if !MEMP_OVERFLOW_CHECK
memp_malloc(memp_t type)
#else
memp_malloc_fn(memp_t type, const char *file, const int line)
#endif
{
    void *memp;
    LWIP_ERROR("memp_malloc: type < MEMP_MAX", (type < MEMP_MAX), return NULL;);

#if MEMP_OVERFLOW_CHECK >= 2
    memp_overflow_check_all();
#endif /* MEMP_OVERFLOW_CHECK >= 2 */

#if !MEMP_OVERFLOW_CHECK
    memp = do_memp_malloc_pool(memp_pools[type]);
#else
    memp = do_memp_malloc_pool_fn(memp_pools[type], file, line);
#endif

    return memp;
}

static void
do_memp_free_pool(const struct memp_desc *desc, void *mem)
{
    struct memp *memp;
    SYS_ARCH_DECL_PROTECT(old_level);

    LWIP_ASSERT("memp_free: mem properly aligned",
                ((mem_ptr_t)mem % MEM_ALIGNMENT) == 0);

    /* cast through void* to get rid of alignment warnings */
    memp = (struct memp *)(void *)((u8_t *)mem - MEMP_SIZE);

    SYS_ARCH_PROTECT(old_level);

#if MEMP_OVERFLOW_CHECK == 1
    memp_overflow_check_element_overflow(memp, desc);
    memp_overflow_check_element_underflow(memp, desc);
#endif /* MEMP_OVERFLOW_CHECK */

#if MEMP_STATS
    desc->stats->used--;
#endif

#if MEMP_MEM_MALLOC
    LWIP_UNUSED_ARG(desc);
    SYS_ARCH_UNPROTECT(old_level);
    mem_free(memp);
#else /* MEMP_MEM_MALLOC */
    memp->next = *desc->tab;
    *desc->tab = memp;

#if MEMP_SANITY_CHECK
    LWIP_ASSERT("memp sanity", memp_sanity(desc));
#endif /* MEMP_SANITY_CHECK */

    SYS_ARCH_UNPROTECT(old_level);
#endif /* !MEMP_MEM_MALLOC */
}

/**
 * Put a custom pool element back into its pool.
 *
 * @param desc the pool where to put mem
 * @param mem the memp element to free
 */
void
memp_free_pool(const struct memp_desc *desc, void *mem)
{
    LWIP_ASSERT("invalid pool desc", desc != NULL);
    if ((desc == NULL) || (mem == NULL))
    {
        return;
    }

    do_memp_free_pool(desc, mem);
}

/**
 * Put an element back into its pool.
 *
 * @param type the pool where to put mem
 * @param mem the memp element to free
 */
void
memp_free(memp_t type, void *mem)
{
#ifdef LWIP_HOOK_MEMP_AVAILABLE
    struct memp *old_first;
#endif

    LWIP_ERROR("memp_free: type < MEMP_MAX", (type < MEMP_MAX), return;);

    if (mem == NULL)
    {
        return;
    }

#if MEMP_OVERFLOW_CHECK >= 2
    memp_overflow_check_all();
#endif /* MEMP_OVERFLOW_CHECK >= 2 */

#ifdef LWIP_HOOK_MEMP_AVAILABLE
    old_first = *memp_pools[type]->tab;
#endif

    do_memp_free_pool(memp_pools[type], mem);

#ifdef LWIP_HOOK_MEMP_AVAILABLE
    if (old_first == NULL)
    {
        LWIP_HOOK_MEMP_AVAILABLE(type);
    }
#endif
}
